1. Technical Field
The present invention relates to a liquid ejecting head that ejects liquid from nozzle openings, a liquid ejecting apparatus having such a liquid ejecting head, and a method for manufacturing such a liquid ejecting head. More particularly, the present invention relates to an ink jet recording head that ejects ink as liquid, an ink jet recording apparatus having such an ink jet recording head, and a method for manufacturing such an ink jet recording head.
2. Related Art
As a typical example of a liquid ejecting head that ejects liquid droplets, there is known an ink jet recording head that ejects ink droplets. For example, a known ink jet recording head includes a flow path forming substrate which has formed therein pressure generating chambers communicated with nozzle openings and communicating portions communicated with the pressure generating chambers, piezoelectric elements which are formed on one surface side of the flow path forming substrate, and a protective substrate which is bonded to the surface of the flow path forming substrate where the piezoelectric elements are formed and which has formed therein a piezoelectric element holding portion for holding the piezoelectric elements. On the protective substrate, an IC is mounted which is a driving circuit for driving the piezoelectric elements. The driving circuit and the piezoelectric elements are connected by a wire bonding method using connection wires, which are configured by conductive wires, via lead electrodes which are led out from electrodes on one side of the piezoelectric elements.
Some protective substrates are configured to protect two rows of piezoelectric elements which are arranged so as to correspond to two rows of opposing pressure generating chambers. In this kind of protective substrate, a through-hole is formed at the central portion thereof so that the connection wires are inserted thereto. In such an ink jet recording head, the lead electrodes and the connection wires are connected at the through-hole portion (for example, see JP-A-2004-148813).
However, in the above-described technique, since the driving circuit and the piezoelectric elements are connected by the wire bonding method, the manufacturing cost will increase and it becomes difficult to achieve a high-density mounting. Moreover, since the driving circuit is planarly arranged on the protective substrate, the size of an actuator portion including the piezoelectric elements will increase, which results in an increase in the manufacturing cost.
Such problems are similarly found in other liquid ejecting heads ejecting droplets of different liquid other than ink as well as the ink jet recording head ejecting ink droplets.